---
title: "CVE-2025-68665: LangChain serialization injection vulnerability enables secret extraction"
url: https://erroneo.us/security/cve/CVE-2025-68665/
description: "CVE-2025-68665 (langchain-ai langchainjs): LangChain is a framework for building LLM-powered applications. Prior to @langchain/core versions 0.3.80 and…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-12-23
date_modified: 2026-10-21
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-68665"
kev: false
cvss: 8.6
epss: 0.00793
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-68665: LangChain serialization injection vulnerability enables secret extraction

**Signal:** Normal patch cycle. No exploitation signal; fix it in your next routine update if you are affected. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.8% , percentile 56: FIRST’s model estimates a 0.8% chance of exploitation activity in the next 30 days, higher than 56% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Editorial verdict: Patch this week. LangGrinch: LangChain Core Serialization Injection — A real design flaw in a library almost every Python agent stack pulls in, but it needs a serialize-then-deserialize path over attacker-influenced data; bump langchain-core in your next routine dependency update.

## What it is

LangChain is a framework for building LLM-powered applications. Prior to @langchain/core versions 0.3.80 and 1.1.8, and prior to langchain versions 0.3.37 and 1.2.3, a serialization injection vulnerability exists in LangChain JS's toJSON() method (and subsequently when string-ifying objects using JSON.stringify(). The method did not escape objects with 'lc' keys when serializing free-form data in kwargs. The 'lc' key is used internally by LangChain to mark serialized objects. When user-controlled data contains this key structure, it is treated as a legitimate LangChain object during deserialization rather than plain user data. This issue has been patched in @langchain/core versions 0.3.80 and 1.1.8, and langchain versions 0.3.37 and 1.2.3

## Affected products (CVE record)

- langchain-ai langchainjs: @langchain/core >= 1.0.0, < 1.1.8, @langchain/core < 0.3.80, langchain >= 1.0.0, < 1.2.3, langchain < 0.3.37

## Severity

- GitHub_M CVSS 3.1: 8.6 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable yes , technical impact partial .
- FIRST EPSS (model of 2026-10-21): 0.79% probability of exploitation activity in the next 30 days; percentile 56.

## Sources

- [CVE.org record CVE-2025-68665](https://www.cve.org/CVERecord?id=CVE-2025-68665)
- [NVD entry CVE-2025-68665](https://nvd.nist.gov/vuln/detail/CVE-2025-68665)
- [github.com](https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-r399-636x-v7f6)
- [github.com](https://github.com/langchain-ai/langchainjs/commit/e5063f9c6e9989ea067dfdff39262b9e7b6aba62)
- [github.com](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain%2Fcore%401.1.8)
- [github.com](https://github.com/langchain-ai/langchainjs/releases/tag/langchain%401.2.3)

---
Source page: https://erroneo.us/security/cve/CVE-2025-68665/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt